The overall objective of the research proposed is to elucidate the interactions of steroid (estradiol) and protein hormones (FSH) in the differentiation of rat ovarian granulosa cells. This will be accomplished by characterizing the intracellular positive feedback effects of FSH and estradiol on components of the FSH response system: FSH receptor, adenylate cyclase, cAMP binding protein, aromatase, and LH receptor. In addition, the research is intended to characterize the cAMP binding protein(s) (regulatory subunits of protein kinase?) and to examine if the synergistic induction of cAMP binding protein(s) by estradiol and FSH involves increased transcription, translation and/or activation. This will be analyzed by using high resolution two dimensional electrophoresis, photoaffinity labeling with 32P-8-azido cAMP and cell free protein synthesis.